Providing an instantaneous visual indication of the fuel efficiency or fuel consumption rate of a vehicle to the operator of the vehicle can be very important. Particularly when the fuel being consumed is very expensive or when a certain distance must be traveled with a fixed amount of fuel.
Generally known apparatus have been proposed for measuring fuel efficiency of a vehicle by performing a calculation of the vehicle distance traveled per unit of fuel. The calculation of vehicle distance traveled per unit of fuel is provided to an indicator such as a meter in the form of an electrical signal. The electrical signal causes the meter to move providing an indication of fuel efficiency or consumption. Representative of such apparatus are U.S. Pat. Nos. 2,250,125, 2,422,240, 2,941,397, 3,058,340, 3,118,302, 3,635,079, 3,812,710, 3,908,451, 3,967,097, 4,008,607, 4,012,949 and 4,054,781.
The apparatus disclosed by the above-referenced patents do not provide simple and easy to use apparatus which can provide an instantaneous measure of the fuel efficiency of a vehicle in miles per gallon.